1. Field of the Invention
The present invention generally relates to data processing systems and, more particularly, to systems for utilizing data from a plurality of data stores in a distributed data base.
2. Description of the Prior Art
Since the development of stored-program, general purpose digital computers and the development of complex programs for processing large amounts of data and management of large databases, a general goal of the function of such machines has been to increase the availability of information to a user in a manner in which the operation of the machine to obtain the desired data does not detract from the assimilation of the data by the operator. The achievement of this goal has been complicated by the many programs which have been developed to efficiently capture, store, retrieve and process particular types of data. For instance, alpha-numeric data is typically handled on a character-by-character basis since a code of limited length is sufficient to specify virtually any character in use in the language of any culture. In contrast, graphic or pictorial data must be captured, stored, retrieved and processed in a manner which will allow reproduction at a high degree of resolution, thus requiring much more data to correspond to the space which might be otherwise occupied by an alphanumeric character. Further, even rudimentary operations on graphic data, such as positioning of an image is largely incompatible with the existence of text syntax and predetermined character positions within a document or in a screen image.
Even alphanumeric data, alone, can present formidable problems of form and context when it must be operated upon efficiently by different applications (e.g. programs). For instance, a word processor will generally articulate data in text strings whereas database programs will provide for capture, storage and retrieval of data based on screens containing fields which are used to categorize data and thus avoid storage of a repeated set of identifiers with the data. Spreadsheets require yet a different format for efficient data storage and processing.
The above types of differences and others, which are necessary to the efficient operation of particular applications limit the efficiency with which data can be shared between those applications. While some conversion programs exist, they are time-consuming and, for that reason, are seldom invoked automatically other than for conversion of text files to the format required for a particular, running, word processor program where the need for such conversion can be assumed upon the command for retrieval of the file.
Consider now, the problem presented by the use of computers to present and manage the large amount of data necessary to monitor a complex operation such as the operation of a manufacturing assembly line. Cost, price and profit projections will typically be handled by a spreadsheet type of program. Design information will be handled by text and graphics applications. Correspondence and documentation will be handled in text files. Procurement data and invoices may be handled as both text files and database screens. Testing, quality control, production and similar types of reports may involve all of the above types of data. It can be readily understood that even with existing forms of machine managers, where a plurality of applications can be more easily invoked from menus and so-called window programs which facilitate multi-processing (e.g. simultaneous running of a plurality of programs between which the user can switch), the necessary data for the efficient management of a manufacturing assembly line or the like is not optimally available. Neither can all possible desired combinations of data be made simultaneously available to a user from different applications, each of which is specific to the reporting of only some of the desired data, without large amounts of processing time for data conversion.
In recent years, both economic and political considerations have led to a trend among manufacturers to produce similar or identical products at different, widely separated locations. Such a plurality of manufacturing lines must be optimally managed, just as single manufacturing lines must be, but with the additional requirement that the resulting products must be absolutely uniform (including quality standards) completely interchangeable and produced at approximately the same cost. In cost considerations, materials procurement, labor costs and availability, distribution costs and design must be continually compared between sites in order to maximize the efficiency of the combination of manufacturing lines and overall cost-effectiveness of the manufacturing effort for the company.
In the past, such communications have been done in forms which increase the number of types of data which must be assimilated by the data processor. In addition to the types of computer database information which could be exchanged electronically and which still results in difficulties of processing and communication to the computer user, the exchange of design and manufacturing data between sites was often done in hard copy form, possibly enhanced by facsimile transmission and image data capture technology. Nevertheless, particularly in matters of automated testing, data was often reduced to hard copy form, transmitted by facsimile, courier or mail and then locally entered on a local database. At least in part, this manual data entry constituted a form of data conversion to enable the more rapid accessing of the data by the different applications which were called upon to process the same. However, such forms of data transmission and recapture in machine usable form caused irregular delays and made them subject to human error. Aside from introducing a reliability factor into the data which might result in inconsistent evaluations of the same initial information, irregular delays are particularly deleterious to efficient management of a plurality of manufacturing lines since current data, derived locally, might be compared with obsolete data from another location, leading to incorrect management decisions.
In addition to the above-noted difficulties presented by different types of data which must be pulled together and coordinated to allow a meaningful comparison between manufacturing lines or other business endeavors, it must be realized that it is unlikely that two manufacturing lines, even if arranged to produce identical products, will be identical and exhibit a one-to-one correspondence between operations. Therefore, in addition to amassing data reflecting the operation of the manufacturing lines, the manager at each site must continually determine the portions of the lines which are sufficiently equivalent to allow comparison and what adjustments in data may be necessary for a meaningful comparison to be made. Thus, in the past, such equivalency determinations were subject to human judgement and might be inconsistent between sites.
Further, it is difficult to accomplish the timely transmittal of necessary information consistent with the maintaining of the desired degree of security since either transcription of data and electronic transmission of data may require particular measures to be taken in regard to such data transmittal. For instance, scrambling or encryption may De necessary for electronic transmission, depending on the degree of security required. By the same token, the use of couriers and personnel with special clearances for data transcription may result in additional delays.
It should be understood that while these considerations and the problems which can result are particularly acute in manufacturing processes, the same considerations and problems exist in many fields of endeavor, such as in architecture, insurance, banking, transportation and the like which are subject to both economic and geographical influences. Therefore, although the invention will be described in terms of geographically distributed manufacturing lines, the applicability of the invention is not so limited and should be considered applicable to any other geographically distributed business endeavor.